title: Effect of non-specifically adsorbed ions on the surface oxidation of Pt(111).
abstract: The oxidation processes of a Pt(111) electrode in alkaline electrolytes depend on non-specifically adsorbed ions according to in situ X-ray diffraction and infrared spectroscopic measurements. In an aqueous solution of LiOH, an OHad adlayer is formed in the first oxidation step of the Pt(111) electrode as a result of the strong interaction between Li(+) and OHad , whereas Pt oxidation proceeds without OHad formation in CsOH solution. Structural analysis by X-ray diffraction indicates that Li(+) is strongly protective against surface roughening caused by subsurface oxidation. Although Cs(+) is situated near the Pt surface, the weak protective effect of Cs(+) results in irreversible surface roughening due to subsurface oxidation.
authors.affiliation: Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, Inage-ku, Chiba, Japan. mnakamura@faculty.chiba-u.jp
authors.forename: Masashi
authors.initials: M
authors.lastname: Nakamura
authors.forename: Yo
authors.initials: Y
authors.lastname: Nakajima
authors.forename: Nagahiro
authors.initials: N
authors.lastname: Hoshi
authors.forename: Hiroo
authors.initials: H
authors.lastname: Tajiri
authors.forename: Osami
authors.initials: O
authors.lastname: Sakata
keywords: IR spectroscopy; X-ray diffraction; electrochemistry; platinum; surface chemistry